Effects of Vitamin D levels and supplementation on atopic dermatitis: A systematic review

Correlation between serum 25(OH)D levels with severity of work-related hand eczema among healthcare workers: a cross-sectional study

Hand eczema (HE) is a common condition seen in medical facilities, particularly during the COVID-19 pandemic. The effects of vitamin D on skin inflammation are diverse. The purpose of this study is to examine the relationship between vitamin D levels in healthcare workers as determined by serum 25(OH)D and the severity of HE. In Indonesia, between September and October of 2022, a cross-sectional design was employed for this analytical descriptive study. The hand eczema severity index was used to determine the severity of HE. Out of the 44 healthcare workers who had HE, the findings indicated that 29 had mild HE, 11 had moderate HE, and 4 had severe HE. Subjects with mild, moderate, and severe HE had mean serum 25(OH)D levels of 17.85 ng/mL, 16.45 ng/mL, and 17.87 ng/mL, respectively, falling into the vitamin D deficiency category. Serum 25(OH)D levels and the severity of HE did not significantly correlate (r=-0.056; p=0.359). Serum 25(OH)D levels did not significantly differ between subjects with mild, moderate, and severe HE. The degree of HE was not negatively correlated with serum 25(OH)D levels.

Using Machine Learning to Identify the Relationships between Demographic, Biochemical, and Lifestyle Parameters and Plasma Vitamin D Concentration in Healthy Premenopausal Chinese Women

INTRODUCTION

Vitamin D plays a vital role in maintaining homeostasis and enhancing the absorption of calcium, an essential component for strengthening bones and preventing osteoporosis. There are many factors known to relate to plasma vitamin D concentration (PVDC). However, most of these studies were performed with traditional statistical methods. Nowadays, machine learning methods (Mach-L) have become new tools in medical research. In the present study, we used four Mach-L methods to explore the relationships between PVDC and demographic, biochemical, and lifestyle factors in a group of healthy premenopausal Chinese women. Our goals were as follows: (1) to evaluate and compare the predictive accuracy of Mach-L and MLR, and (2) to establish a hierarchy of the significance of the aforementioned factors related to PVDC.

METHODS

Five hundred ninety-three healthy Chinese women were enrolled. In total, there were 35 variables recorded, including demographic, biochemical, and lifestyle information. The dependent variable was 25-OH vitamin D (PVDC), and all other variables were the independent variables. Multiple linear regression (MLR) was regarded as the benchmark for comparison. Four Mach-L methods were applied (random forest (RF), stochastic gradient boosting (SGB), extreme gradient boosting (XGBoost), and elastic net). Each method would produce several estimation errors. The smaller these errors were, the better the model was.

RESULTS

Pearson's correlation, age, glycated hemoglobin, HDL-cholesterol, LDL-cholesterol, and hemoglobin were positively correlated to PVDC, whereas eGFR was negatively correlated to PVDC. The Mach-L methods yielded smaller estimation errors for all five parameters, which indicated that they were better methods than the MLR model. After averaging the importance percentage from the four Mach-L methods, a rank of importance could be obtained. Age was the most important factor, followed by plasma insulin level, TSH, spouse status, LDH, and ALP.

CONCLUSIONS

In a healthy Chinese premenopausal cohort using four different Mach-L methods, age was found to be the most important factor related to PVDC, followed by plasma insulin level, TSH, spouse status, LDH, and ALP.

Efficacy of vitamin D supplementation on the severity of atopic dermatitis in children: A systematic review and meta-analysis

Background: Atopic Dermatitis (AD) is a common dermatosis in children, that includes skin architecture defects, immune dysregulation, and changes of skin flora. Several new drugs have been found to reduce the severity of AD. Vitamin D is one of the new therapies that is still controversial. The purpose of this research is to conclude the efficacy of vitamin D on atopic dermatitis severity in children aged 0-18 years old. Methods: A systematic search was conducted on the PubMed, Cochrane, ProQuest, Google Scholar, Clinical Trial website, and university repositories including studies published from January 2010 through October 2020. We compared populations, intervention, study design, and outcomes. Statistical analysis was done with Review Manager 5.4.1. Results: Eight articles met eligibility and inclusion criteria, four articles provided complete data and were analysed. Not all studies demonstrated the efficacy of vitamin D but a meta-analysis of four studies of vitamin D supplementation vs placebo found a mean difference of -0.93 (95%CI -1.76, to -0.11, p<0.001) of patient outcome, but statistically, there was no difference in cure rate (risk ratio 1.46 (95%CI 0.72, to 2.97, p=0.008) in vitamin D supplementation groups compared to placebo groups. Conclusions: Vitamin D supplementation in paediatric atopic dermatitis patients could offer improvement of disease severity but the recommended dose and duration of administration cannot be concluded yet.

Sex and obesity status modify the association between vitamin D and eczema among adolescents

BACKGROUND

Epidemiologic studies have reported inconsistent associations between vitamin D and eczema. This study sought to assess whether sex and obesity status could modify the association between vitamin D and eczema.

METHODS

A cross-sectional study enrolled 763 adolescents in Kuwait. 25-hydroxyvitamin D (25(OH)D) was measured in venous blood. Current eczema was defined according to clinical history and characteristic morphology and distribution.

RESULTS

In sex-stratified analysis, decreased 25(OH)D levels were associated with increased current eczema prevalence among males (adjusted odds ratio (aOR)tertile 1 vs. tertile 3: 2.14, 95% confidence intervals (CI): 1.07-4.56), but not among females (aORtertile 1 vs. tertile 3: 1.08, 95% CI: 0.71-1.66). Further stratification by obesity status showed that lower 25(OH)D levels were associated with increased current eczema prevalence among overweight/obese males (per 10-unit decrease in 25(OH)D levels: aOR: 1.70, 95% CI: 1.17-2.46). Such an association was weaker and statistically non-significant among overweight/obese females (per 10-unit decrease in 25(OH)D levels: aOR: 1.26, 95% CI: 0.93-1.70).

CONCLUSIONS

Sex and obesity status modified the association between vitamin D levels and eczema, with an inverse association observed among overweight/obese males, but not among overweight/obese females. These results suggest that preventive and clinical management strategies could vary by sex and obesity status.

IMPACT

The current study showed that sex and obesity modify the association between vitamin D and eczema among adolescents. An inverse association between vitamin D and eczema was observed among overweight/obese males, but this association was not as pronounced among overweight/obese females. Vitamin D was not associated with eczema among underweight/normal weight males and females. The identification of effect modification by sex and obesity status add to the current scientific knowledge and further highlight the complexity of the association between vitamin D and eczema. These results may promote a more individualized approach to the future prevention and clinical management of eczema.

The effect of fatty acids, vitamins, and minerals on pediatric atopic dermatitis: A systematic review

BACKGROUND

A body of research has examined the role of fatty acid (FA), vitamin, and mineral supplementation as adjunctive treatment for atopic dermatitis (AD); however, results are conflicting and concrete recommendations are lacking. The objective of this study is to highlight the role of these nutrients in alleviating AD severity and provide the clinician with consolidated information that can be used to make recommendations to the pediatric patient and caretaker, where this topic is of high interest.

METHODS

A review of the PubMed and Embase databases was conducted to identify and qualitatively analyze all randomized controlled trials, systematic reviews, and meta-analyses conducted within the last 21 years regarding use of these nutrients to alleviate symptoms of AD. Inclusion criteria include AD diagnosis, non-infant age groups, and AD severity outcomes; exclusion criteria include preventative studies, predominantly maternal or infant demographics, or nonclinical outcomes.

RESULTS

Sixty-nine studies were included. Evidence regarding FA supplementation is inconclusive; however, targeting an ideal omega-3:omega-6 FA ratio may play a small role in alleviating AD symptoms. Studies results regarding vitamin/mineral supplementation are inconsistent and supplementation should not be advised unless the patient has a documented deficiency.

CONCLUSION

Pediatric AD patients should lead a healthy lifestyle with an emphasis on consumption of wholesome foods. Nutritional supplementation can play a role in improving AD symptoms; however, this should be evaluated on a case-by-case basis. Limitations include heterogeneity of studies.

Oral vitamin D modulates the epidermal expression of the vitamin D receptor and cathelicidin in children with atopic dermatitis

Although vitamin D (VD) is known to have multiple effects on the skin and immunity, its effects on atopic dermatitis (AD) severity remain unclear. We investigated whether oral cholecalciferol (VD3) supplementation changes stratum corneum expression of the vitamin D receptor (vdr), and the epidermal alarmins Cathelicidin Antimicrobial Peptide (camp/LL-37) and Thymic Stromal Lymphopoietin (tslp) in children with AD. We conducted an open-label supplementation study with weekly oral VD3 for six weeks in children with AD. Serum 25-hydroxyvitamin D (25OHD), lesional Staphylococcus aureus colonization, and AD severity evaluated by SCORAD index were evaluated before and after supplementation. Tape stripping (TS) was performed on non-lesional and lesional skin to measure mRNA expression of vdr, camp, and tslp through RT-qPCR and LL-37 peptide by ELISA. Twenty-two children with moderate-severe AD received weekly oral VD3 for six weeks. Total serum 25OHD increased from 45.1 ± 23 to 93.5 ± 24.3 nmoL/L (p < 0.0001), while SCORAD decreased from 41.4 ± 13.5 to 31.5 ± 15.8 (p < 0.0001). After treatment, epidermal gene expression of camp increased significantly in non-lesional (p = 0.014) and lesional (p = 0.0007) tape stripping samples, while vdr only increased in lesional skin samples (p < 0.0001). LL-37 peptide increased significantly only in lesional skin samples (p = 0.008). Gene expression of tslp did not change after oral VD3 treatment. In children with AD, oral VD3 supplementation was associated with improved VD status and AD severity, as well as increased VDR and Cathelicidin expression in lesional skin, which provide mechanistic clues on its effects.

Vitamin D supplementation for patients with alopecia areata: A protocol for systematic review and meta-analysis

BACKGROUND

Several studies have reported an association between low Vitamin D (VD) levels and Alopecia areata (AA), and suggested VD preparations as a potential therapy. VD has immunomodulatory function closely associated with a variety of skin diseases, but there is no conclusive evidence to support VD supplementation for patients with AA. Therefore, we will conduct a meta-analysis to collect and evaluate the efficacy and safety of VD supplementation in the treatment of AA.

METHODS

We will search the following databases according to the developed strategy: Cochrane Library, PubMed, Web of Science, EMBASE, Scopus, Google scholar for Randomized controlled trials related to VD supplementation for AA. The retrieval time is from the establishment of each database to July 2022. Two reviewers will independently complete the literature search and screening, risk of bias assessment and data extraction. Severity of Alopecia Tool, Alopecia Density and Extent, Lesional area and senstivity (score) will be the primary results. RevMan V.5.3 will be used for data analysis and synthesis. For dichotomous outcomes and the continuous outcomes, we will calculate risk ratio with 95% Confidence intervals and mean differences or standardized mean differences with 95% Confidence intervals respectively. The reporting bias will be investigated using funnel plots, and the asymmetry of the funnel plots will be explained using the Harbord modified test or the Egger's regression test.

RESULTS

The results of the study expect to provide a high-quality, evidence-based recommendation on VD supplementation in the treatment of AA for clinicians.

CONCLUSIONS

The study will provide scientific and useful evidence for better use of VD supplementation in treating AA.

Low socioeconomic status predicts vitamin D status in a cross-section of Irish children

Vitamin D is essential for bone and muscle health with adequate status in childhood crucial for normal skeletal development. We aimed to investigate vitamin D status in a convenience sample (n = 1226) of Irish children (aged 1-17 years) who had serum 25-hydroxyvitamin D (25(OH)D) tested by request of their GP at a Dublin Hospital between 2014 and 2020. We examined predictors including age, sex, season and socioeconomic status (SES). Vitamin D deficiency (<30 nmol/l) was prevalent affecting 23 % and was more common in disadvantaged areas (34 %) and in those aged >12 v. ≤12 years (24 % v. 16 %, P = 0⋅033). The greatest predictor was SES (disadvantaged v. affluent, OR 2⋅18, CI 1⋅34, 3⋅53, P = 0⋅002), followed by female sex (OR 1⋅57, CI 1⋅15, 2⋅14, P = 0⋅005) and winter season (October to February, OR 1⋅40, CI 1⋅07, 1⋅84, P = 0⋅015). A quarter of our sample of children were deficient, rising to one-third in those in disadvantaged areas. Females and those aged over 12 years had a higher prevalence of deficiency. Public health strategies to improve vitamin D status in Irish children, including systematic food fortification may need to be considered to address this issue.

Efficacy of vitamin D supplementation on the severity of atopic dermatitis in children: A systematic review and meta-analysis

Background: Atopic Dermatitis (AD) is a common dermatosis in children, that includes skin architecture defects, immune dysregulation, and changes of skin flora. Several new drugs have been found to reduce the severity of AD. Vitamin D is one of the new therapies that is still controversial. The purpose of this research is to conclude the efficacy of vitamin D on atopic dermatitis severity in children aged 0-18 years old. Methods: A systematic search was conducted on the PubMed, Cochrane, ProQuest, Google Scholar, Clinical Trial website, and university repositories including studies published from January 2010 through October 2020. We compared populations, intervention, study design, and outcomes. Statistical analysis was done with Review Manager 5.4.1. Results: Eight articles met eligibility and inclusion criteria, four articles provided complete data and were analysed. Not all studies demonstrated the efficacy of vitamin D but a meta-analysis of four studies of vitamin D supplementation vs placebo found a mean difference of -0.93 (95%CI -1.76, to -0.11, p<0.001) of patient outcome, but statistically, there was no difference in cure rate (risk ratio 1.46 (95%CI 0.72, to 2.97, p=0.008) in vitamin D supplementation groups compared to placebo groups. Conclusions: Vitamin D supplementation in paediatric atopic dermatitis patients could offer improvement of disease severity but the recommended dose and duration of administration cannot be concluded yet.

What are the highest yielding search strategy terms for systematic reviews in atopic dermatitis? A systematic review

The impact of search strategies on systematic reviews (SR) of atopic dermatitis (AD) is unknown. The purpose of this review was to evaluate search strategies used in SR of AD and their impact on the frequency of manuscripts identified. MEDLINE and EMBASE were searched for SR related to AD. Simulations were performed by running combinations of search terms in MEDLINE and EMBASE. Overall, 250 SR met inclusion criteria, of which 225 specified search strategies. SR using 5-6 terms (20.0% to 12.1%) or ≥ 7 (40.0% to 18.8%) terms decreased, whereas SR using 3-4 terms numerically increased (18.8% to 30.2%) and 1-2 terms remained similar (37.5% to 38.9%) from 1999-2009 to 2015-2019. The most commonly searched terms were "atopic dermatitis" (n = 166), followed by "eczema" (n = 156), "dermatitis atopic'" (n = 81), "atopic eczema" (n = 74), "neurodermatitis" (n = 59), "Besniers prurigo" (n = 29), "infantile eczema" (n = 27), and "childhood eczema" (n = 19). Simulations revealed that "eczema" and "atopic dermatitis" yielded the most hits. The number of search terms that maximized hits in MEDLINE and EMBASE was 5 and 4, respectively. Search strategies for AD were heterogeneous, with high proportions of search strategies providing few search hits. Future studies should use standardized and optimized search terms.

Influence of climate factors on pediatric alopecia areata flares in Philadelphia, Pennsylvania

Patients with alopecia areata (AA) may experience episodic disease flares characterized by increasing hair loss that follow a seasonal pattern. However, no studies have examined whether specific climate factors contribute to the seasonal pattern of AA flares. Using Spearman rank correlation analyses, we assessed the association between climate variables and AA flare frequency per month in 336 children with AA in Philadelphia, Pennsylvania. Region-specific monthly values for average ambient temperature, air pressure, cloudiness, hours of sunlight, relative humidity, number of days with sun, number of days with rain, volume of precipitation, wind gust, wind speed, and UV index from January 2015 to December 2017 were obtained from World Weather Online. We found significant (P < 0.05) correlations between AA flare frequency and UV index (R = − 0.66), precipitation (R = − 0.66), number of days with rain (R = − 0.70), number of days with sun (R = 0.62), and air pressure (R = 0.80). Stratified analyses showed even stronger associations with UV index and precipitation in patients with an atopic comorbidity. New significant correlations appeared with temperature, wind speed, and UV index of the prior month. However, in patients who did not have atopic comorbidities, we generally observed weaker and non-significant correlations between climate and AA flare frequency. This study suggests that certain climate factors may mediate the seasonal pattern of AA flares and may contribute to AA pathogenesis. Atopic AA patients may be more susceptible to the influence of climate compared to those with no history of atopy.

Vitamin D receptor gene polymorphisms in atopy

Background

The occurrence of allergic conditions, for example allergic asthma, rhinitis, and atopic dermatitis, is rising worldwide. These allergic conditions are associated with poor life quality. Vitamin D is proposed to be linked with increased risk and severe forms of allergic diseases.

Aims

This review article aimed to evaluate the vitamin D level role and polymorphisms of vitamin D receptor gene (VDR) in atopy.

Methods & Materials

We analyzed publications that were focusing on levels of vitamin D and/or polymorphism analysis of vitamin D receptor gene in allergic asthma, rhinitis, and atopic dermatitis patients.

Results

We noticed that levels of vitamin D are extensively studied in atopy by many research groups, however, polymorphisms of vitamin D receptor gene and their link with levels of vitamin D lack comprehensive data. There is evidence that vitamin D may be associated with anti‐inflammatory effects in allergic diseases. Some of VDR polymorphisms also may play a role in pathogenesis of these diseases. However, the data from different studies are controversial.

Discussion

The results of different studies are usually inconsistent, most probably due to populational bias or differences in methodology. Even though, more evidence shows a positive impact of vitamin D on the risk and outcomes of allergic diseases, especially atopic dermatitis, and asthma.

Conclusions

There is controversial data about the level of vitamin D and its role in atopy; however, more evidence shows a positive impact on the risk and outcomes of allergic diseases.

Rickets and gross motor delay in a child with atopic dermatitis

We report a case of a 14-month-old boy with atopic dermatitis (AD) who presented to our hospital with hypocalcemic tetany and gross motor delay. Further laboratory and imaging confirmed the diagnosis of vitamin D deficiency and rickets. He was breastfeeding and on a restricted diet due to presumed multiple food allergies. He received calcium and vitamin D supplementation which corrected his hypocalcemia. The patient developed Staphylococcus aureus bacteremia and superficial septic thrombophlebitis for which he was treated with antibiotics and anticoagulation. An elimination diet should be avoided in AD patients as true food-induced AD is rare and management should focus on optimal skincare. AD patients have a higher rate of S. aureus skin colonization, which increases their risk for infectious complications. This case also highlights the importance of maintaining a high index of suspicion for rickets in children with isolated gross motor delay, especially in those with risk factors.

The Role of Genetics, the Environment, and Epigenetics in Atopic Dermatitis

Atopic Dermatitis (AD) is a common inflammatory disease with a genetic background. The prevalence of AD has been increasing in many countries. AD patients often have manifestations of pruritus, generalized skin dryness, and eczematous lesions. The pathogenesis of AD is complicated. The impaired skin barrier and immune imbalance play significant roles in the development of AD. Environmental factors such as allergens and pollutants are associated with the increasing prevalence. Many genetic and environmental factors induce a skin barrier deficiency, and this can lead to immune imbalance, which exacerbates the impaired skin barrier to form a vicious cycle (outside-inside-outside view). Genetic studies find many gene mutations and genetic variants, such as filaggrin mutations, which may directly induce the deficiency of the skin barrier and immune system. Epigenetic studies provide a connection between the relationship of an impaired skin barrier and immune and environmental factors, such as tobacco exposure, pollutants, microbes, and diet and nutrients. AD is a multigene disease, and thus there are many targets for regulation of expression of these genes which may contribute to the pathogenesis of AD. However, the epigenetic regulation of environmental factors in AD pathogenesis still needs to be further researched.

The association between atopic dermatitis and serum 25-hydroxyvitamin D in children: Influence of sun exposure, diet, and atopy features-A cross-sectional study

BACKGROUND

Previous studies have linked low serum vitamin D (VD) or 25-hydroxyvitamin D (25(OH)D) levels with increased severity of atopic dermatitis (AD) in children.

OBJECTIVE

To investigate the association between serum VD (25(OH)D) levels and AD and AD severity, considering the influence of diet and sun exposure.

METHODS

We performed a prospective cross-sectional study of healthy controls and children diagnosed with AD. Participants were recruited between January 2011 and December 2012, and the following parameters were assessed: age, sex, body mass index (BMI), AD severity, Fitzpatrick skin type, asthma and rhinitis history, dietary VD intake, daily potential sun-induced VD production, sunscreen use, 25(OH)D and IgE serum levels, and results of the ImmunoCAP Phadiatop Infant test.

RESULTS

The study population consisted of 105 healthy controls and 134 AD patients. Serum 25(OH)D levels were significantly lower in moderate and severe AD than in mild AD, although this association was only significant for patients with light Fitzpatrick skin type (mean(SD) 36.7 (11.9) ng/mL; moderate 28.8 [11.5] ng/mL; and severe 27.6 [12.1] ng/mL, P = .045). Logistic regression analysis revealed a positive association between severe AD and both positive ImmunoCAP Phadiatop test and BMI.

CONCLUSION

Our data support an association between VD deficiency and AD severity only in patients with light complexion.

Vitamin D prescribing in children in UK primary care practices: a population-based cohort study

OBJECTIVE

To examine temporal changes in the incidence and patterns of vitamin D supplementation prescribing by general practitioners (GPs) between 2008 and 2016.

DESIGN

Population-based cohort study.

SETTING

UK general practice health records from The Health Improvement Network.

PARTICIPANTS

Children aged 0 to 17 years who were registered with their general practices for at least 3 months.

OUTCOME MEASURES

Annual incidence rates of vitamin D prescriptions were calculated, and rate ratios were estimated using multivariable Poisson regression to explore differences by sociodemographic factors. Data on the type of supplementation, dose, dosing schedule, linked 25-hydroxyvitamin D (25(OH)D) laboratory test results and clinical symptoms suggestive of vitamin D deficiency were analysed.

RESULTS

Among 2 million children, the crude annual incidence of vitamin D prescribing increased by 26-fold between 2008 and 2016 rising from 10.8 (95% CI: 8.9 to 13.1) to 276.8 (95% CI: 264.3 to 289.9) per 100 000 person-years. Older children, non-white ethnicity and general practices in England (compared with Wales/Scotland/Northern Ireland) were independently associated with higher rates of prescribing. Analyses of incident prescriptions showed inconsistent supplementation regimens with an absence of pre-supplementation 25(OH)D concentrations in 28.7% to 56.4% of prescriptions annually. There was an increasing trend in prescribing at pharmacological doses irrespective of 25(OH)D concentrations, deviating in part from UK recommendations. Prescribing at pharmacological doses for children with deficient status increased from 3.8% to 79.4%, but the rise was also observed in children for whom guidelines recommended prevention doses (0% to 53%). Vitamin D supplementation at pharmacological doses was also prescribed in at least 40% of children with no pre-supplementation 25(OH)D concentrations annually.

CONCLUSIONS

There has been a marked and sustained increase in vitamin D supplementation prescribing in children in UK primary care. Our data suggests that national guidelines on vitamin D supplementation for children are not consistently followed by GPs.

Assessment of the Effectiveness of Vitamin Supplement in Treating Eczema: A Systematic Review and Meta-Analysis

Background

The morbidity of eczema has increased in the recent years, and the methods to prevent or ameliorate its effects are becoming more important. To this end, this research was conducted to determine the effectiveness of vitamin supplements in eczema therapy.

Method

Embase, PubMed, and Cochrane Central Register of Clinical Trials were searched. Only randomized controlled trials were included, and we included all quantified eligible data where the SCORing Atopic Dermatitis (SCORAD) Index or Eczema Area and Severity Index (EASI) scores were applied to assess the severity of eczema.

Results

Ten studies fulfilled the inclusion criteria, and eight of them were included for quantitative analysis (total: 456 patients). Compared to the controls, the SCORAD index or EASI decreased in the vitamin supplement group (mean difference -5.96, 95% CI: -7.69 to -4.23 for vitamin D3; mean difference -5.72, 95% CI: -11.41 to -0.03 for vitamin E; and mean difference -3.19, 95% CI: -4.27 to -2.10 for vitamin B12).

Conclusion

This study suggests that vitamin supplements could be important therapeutics to help manage eczema patients.

Managing atopic dermatitis with systemic therapies in adults and adolescents: An Australian/New Zealand narrative

With the rapid development of new, targeted therapies for the treatment of moderate/severe atopic dermatitis, it is opportune to review the available conventional systemic agents. We assess the published evidence for systemic therapies for atopic dermatitis and amalgamate this with real-world experience. Discussions are centred on when systemic therapy should be considered, which drug(s), what dose, how to sequence or combine these therapies, how long they should be continued for and what is considered success.

Vitamin D Deficiency and Effects of Vitamin D Supplementation on Disease Severity in Patients with Atopic Dermatitis: A Systematic Review and Meta-Analysis in Adults and Children

Research has investigated 25-hydroxyvitamin D (25(OH)D) levels in the Atopic Dermatitis (AD) population, as well as changes in AD severity after vitamin D (VitD) supplementation. We performed an up-to-date systematic review and meta-analysis of these findings. Electronic searches of MEDLINE, EMBASE and COCHRANE up to February 2018 were performed. Observational studies comparing 25(OH)D between AD patients and controls, as well as trials documenting baseline serum 25(OH)D levels and clinical severity by either SCORAD/EASI scores, were included. Of the 1085 articles retrieved, sixteen were included. A meta-analysis of eleven studies of AD patients vs. healthy controls (HC) found a mean difference of −14 nmol/L (95% CI −25 to −2) for all studies and −16 nmol/L (95% CI −31 to −1) for the paediatric studies alone. A meta-analysis of three VitD supplementation trials found lower SCORAD by −11 points (95% CI −13 to −9, p < 0.00001). This surpasses the Minimal Clinical Important Difference for AD of 9.0 points (by 22%). There were greater improvements in trials lasting three months and the mean weighted dose of all trials was 1500–1600 IU/daily. Overall, the AD population, especially the paediatric subset, may be at high-risk for lower serum 25(OH)D. Supplementation with around 1600 IU/daily results in a clinically meaningful AD severity reduction.

Vitamin D modulates the allergic phenotype of dendritic cells in children with atopic dermatitis

Vitamin D (VD) deficiency has been associated with increased incidence and severity of atopic dermatitis (AD), but the mechanisms through which VD may ameliorate AD are unclear. We compared the phenotypic characteristics of circulating myeloid and plasmacytoid dendritic cells (mDCs and pDCs, respectively) of children with AD vs healthy controls (HC) and evaluated if VD can modulate the allergic phenotype of circulating DCs in AD patients. Although there was no difference in frequency of circulating DCs between groups, among children with AD there was an inverse correlation between SCORAD and circulating total DCs and mDCs. In AD, serum IgE concentration correlated with FcεRI and surface-bound IgE expression on mDCs and pDCs; pDCs expressing FcεRI and IgE were significantly increased compared to HC. Ex vivo, 1,25(OH)₂ D₃ significantly decreased FcεRI expression on mDCs and surface-bound IgE on mDCs and pDCs. Oral VD supplementation reduced expression of surface-bound IgE on pDCs in children with AD. In summary, VD decreases the allergic phenotype of circulating DCs in children with AD, a potential mechanism for how VD supplementation may improve AD severity. Future studies are needed to further assess the role of VD supplementation as an immunomodulatory therapy for AD.